My previous attempts with creating patina on copper have been mostly using commercial methods, patina mix you can buy at the store (like liver of sulfur). ( I talked about this in a previous post “Revisited Inspirations”.) I’ve been reading about various “home methods” and after some experimentation I think I have finally figured out how to get the results I want! I first tried burying the copper pieces in a mix of salt and ammonia. For days I’ve been changing the mix and gotten uneven results (a small part of the piece would get blue patina and rest would just darken). I kept adding salt or adding ammonia thinking the ratio of the two is the key. I finally read about this method “fumigation” – you suspend the pieces in a container, sprinkle the salt on and let the ammonia fume the pieces. The results are awesome, I’m getting the exact bright blue color I want ( and it doesn’t take four days!) You can get the patina more even as long as you sprinkle the salt evenly and then you can watch it change. (Yes, I’m standing around with a flash light pointed at the pieces to see every little detail that happens…)
I also tried a modified “bury method” where you moisten paper towels with the ammonia, place the pieces in between them and sprinkle the salt on the towels. You seal the container and check it every once in a while. That seemed to also work, you just can’t watch it all happen.
It seems that experimenting is the only way to get what you want, there is no exact formula if you’re using home made ingredients. But on the other hand, that ‘s the fun part of the whole process! You get surprises – good and bad – and learn at the same time. Now I just need to wait for the pieces to dry out completely and then seal them. I meant to use the round shapes in some of my riveting experiments, but I might not want to cover the beautiful patina now with another layer of metal. Back to making more copper shapes!